DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (https://www.diychatroom.com/)
-   Electrical (https://www.diychatroom.com/f18/)
-   -   If it's 80 ft long wire (20amps) a considerable problem for voltage drop? (https://www.diychatroom.com/f18/if-its-80-ft-long-wire-20amps-considerable-problem-voltage-drop-657899/)

rockman413 04-24-2019 02:54 PM

If it's 80 ft long wire (20amps) a considerable problem for voltage drop?
 
Hi there,
So I'm going to have 20 amps wire as long as 80 ft from the subpanel , via a junction box, to devices. Should I take "voltage drop" into consideration that it's best to install another subpanel instead of the junction box, although it cost me more to move the AC condenser which is now in the front of the junction box/subpanel location.

Thanks

KPDMinc 04-24-2019 04:41 PM

Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?
 
1 Attachment(s)
should be fine - my house is over 80' long (panel is at one end) and no circuits have aver been affected by voltage drop...

found this:

rockman413 04-24-2019 04:51 PM

Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?
 
Quote:

Originally Posted by KPDMinc (Post 5820047)
should be fine - my house is over 80' long (panel is at one end) and no circuits have aver been affected by voltage drop...

found this:

Thanks. My house is like 40 feet from subpanel to junction box, and then from junction box to all the outlet it can vary from 10 feet to 40 feet, so the total length is between 50 feet to 80 feet.

By the way, I'm in Los Angeles, is the power coming into the house 110V or 120V?

KPDMinc 04-24-2019 05:04 PM

Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?
 
Quote:

Originally Posted by rockman413 (Post 5820059)
Thanks. My house is like 40 feet from subpanel to junction box, and then from junction box to all the outlet it can vary from 10 feet to 40 feet, so the total length is between 50 feet to 80 feet.

By the way, I'm in Los Angeles, is the power coming into the house 110V or 120V?

have to measure to find out the actual voltage

CodeMatters 04-24-2019 05:15 PM

Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?
 
Our code allows #12 to be used on a 20A breaker up to max length of
50m (164ft). While not code outside of Canada, this probably wouldn't
be a bad guide line.
Code ref Table 68.

Jim Port 04-24-2019 05:50 PM

Nominal US voltage.is 120/240.

rockman413 04-24-2019 06:19 PM

Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?
 
Quote:

Originally Posted by CodeMatters (Post 5820089)
Our code allows #12 to be used on a 20A breaker up to max length of
50m (164ft). While not code outside of Canada, this probably wouldn't
be a bad guide line.
Code ref Table 68.

Is the outlet , which I think is a 20A circuit, normally is a Gauge 12 or Gauge 14 wire?

CodeMatters 04-24-2019 06:37 PM

Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?
 
Quote:

Originally Posted by rockman413 (Post 5820139)
Is the outlet , which I think is a 20A circuit, normally is a Gauge 12 or Gauge 14 wire?


20A breaker will normally feed #12 wire.

CodeMatters 04-24-2019 06:39 PM

Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?
 
Quote:

Originally Posted by Jim Port (Post 5820113)
Nominal US voltage.is 120/240.


Also be accurate to say North American nominal voltage is 120/240.

rockman413 04-24-2019 07:24 PM

Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?
 
Quote:

Originally Posted by CodeMatters (Post 5820151)
Also be accurate to say North American nominal voltage is 120/240.

So I'm having a 5volt voltage drop, I may end up at 115V, since most devices is made for 110V-120V, even I got this home run wires in my house up to 80 Feet, I'm still good because 115V is > 110V, am I correct?

So need to move the AC or do a subpanel, just do junction box.

Sdiver2489 04-24-2019 09:08 PM

Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?
 
Quote:

Originally Posted by rockman413 (Post 5820179)
So I'm having a 5volt voltage drop, I may end up at 115V, since most devices is made for 110V-120V, even I got this home run wires in my house up to 80 Feet, I'm still good because 115V is > 110V, am I correct?

So need to move the AC or do a subpanel, just do junction box.

By my calculations you will actually drop only 2.5V over 80 feet. You are fine.

rockman413 04-24-2019 10:48 PM

Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?
 
Quote:

Originally Posted by rockman413 (Post 5820179)
So I'm having a 5volt voltage drop, I may end up at 115V, since most devices is made for 110V-120V, even I got this home run wires in my house up to 80 Feet, I'm still good because 115V is > 110V, am I correct?

So need to move the AC or do a subpanel, just do junction box.


Sorry, I mean, So NO need to move the ac or do a subpanel, just do a junction box.

rockman413 04-24-2019 11:02 PM

Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?
 
Quote:

Originally Posted by Sdiver2489 (Post 5820273)
By my calculations you will actually drop only 2.5V over 80 feet. You are fine.

Why your calculation is very different from KPD's (see the 2nd or 3rd post)

Shadow99 04-25-2019 07:25 AM

Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?
 
Quote:

Originally Posted by rockman413 (Post 5820337)
Why your calculation is very different from KPD's (see the 2nd or 3rd post)

You're getting a few answers, but to properly advise you, we need the details.

Is this a 80' run to an AC unit? Most likely 240V
To do the voltage drop, we need the voltage and current of the AC unit.

If you are just running general purpose receptacles, then what @CodeMatters said will be fine.

bob22 04-25-2019 08:49 AM

Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?
 
Southwire has a calculator that when I ran it for 80 feet delivering 20 amps said you need 10 awg.
Site:
https://www.southwire.com/calculator-vdrop


All times are GMT -5. The time now is 06:26 AM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.